Slit lamp



March 18, 1941. w, JQBE 2,235,319

SLIT LAMP Filed Sept. 50 1939 s Sheets-Sheet 1 W! 1' II m FREDEREQK w. 305E INVENTOR BY WM,

ATTo k is March 18, 1941. E w JOBE 2,235,319

SLIT LAMP Filed Sept. 30, 1939 3 Sheets-Sheet 2 FIG 2 1| FREDERl -K w. JOBE INVENTER BY v I F. W. JOBE SLIT LAMP March 18, 1941.

File d Sept. 30. 1939 s Shet-Sheet s Patented Mar. 18, 1941 SLIT LAMP Frederick W. Jobe, Rochester, N. Y., assignor to Bansch & Lomb Optical Company, Rochester, N. Y., a corporation of New York Application September 30, 1939, Serial No. 297,402

3 Claims.

The present invention relates to ophthalmic instruments and more particularly to ophthalmic instruments of the type known as slit lamps.

One of the objects of the present invention is 5. to provide a new and improved slit lamp which is simple and convenient to use yet rugged, compact and accurate in construction. Another object is to provide a slit lamp in which the slit lamp projector and microscope can be moved angularly either separately or together without the need for refocusing. A further object is to provide a slit lamp in which both eyes of a patient may be examined without moving the patients head. These and other objects and advantages 15. reside in certain novel features of construction, arrangement and combination of parts as will hereinafter be more fully set forth and pointed out in the appended claims.

Referring to the drawings:

Fig. 1 is a front perspective view of my new slit lamp.

Fig. 2 is a top plan view of the carriage.

Fig. 3 is a front elevation of the carriage with parts in section.

Fig. 4 is a vertical section of the carriage taken on line 4-4 of Fig. 3.

Fig. 5 is a rear elevation of my slit lamp microscope with parts in section.

Fig. 6 is a section taken on line 8-5 of Fig. 5.

Fig. 7 is an enlarged fragmentary elevation of the microscope arm joint.

Fig. 8 is a horizontal section taken on line 88 of Fig. 5.

One preferred form of my invention is illustrated in the drawings wherein H designates the instrument base which may be supported on any suitable stand or table. A standard it, fastened at the rear end of the base by screws or bolts l3, overhangs the base H and carries a chin rest M which may be raised or lowered by a nut l5. The usual forehead rest It is removably fastened by screws IT to a bracket is which is pivotally mounted on the standard 12 beneath the chin rest I4. A screw l9 serves to tilt the bracket |8 a and forehead rest |5 forward and backward relative to the chin rest M. The chin rest and forehead rest are provided to fix the head of the patient under observation and their particular structures form no part of the present invention. Suitable devices for positioning the head of a patient are well known to persons skilled in the art.

A stub shaft 2| is fixed at its ends in two projections 22 and extends transversely across the rear portion of the base beneath the chin rest l4 and forehead rest |5. A carriage 23 has a rear portion 24 formed with a bore 25 which fits snugly around the stub shaft 2| and is slidable on the stub shaft 2| between the projections 22.

The base H is formed with a slot 23 in front of andparallel to the stub shaft 2| and a track 21 is fixed in this slot 26. The front of the carriage 23 is provided with two housings 28 one at each end, and a ball bearing assembly 29 is fixed on a shaft 3| in each housing. The outer race 32 of each ball bearing assembly 29 rests on the track 21 and serves as a roller or wheel for the carriage 23.

Between the stub shaft 2| and the slot 25, the base II has a large opening 33. A bracket 34 is fastened. beneath the center of the carriage 23 by a screw 35 and projects forwardly beneath the base beyond the slot 26. Directly beneath the slot-2t and track 21, the bracket 34 is recessed and a ball bearing assembly 36 is secured in this recess by a screw or bolt 31. The outer race 38 of the ball bearing assembly 33 bears against the under side of the track 21.

In order to prevent any looseness between the carriage 23 and the track 21, the bracket 34 is formed with a deep slot 39 at the elbow. A stud bolt 4| is threaded into the bottom of the carriage 23 and projects downwardly through a hole 42 in the bracket 34. A nut 43 is threaded on the lower end of the stud bolt 4| and serves to draw the outer end of the bracket 34 upward toward the carriage to clamp the track 21 tightly between the races 32 and 38 of the ball bearing assemblies 29 and 36. The usual lock nut 44 may be used on the stud bolt 4| if desired.

A heavy leaf spring 45 is secured to the bottom of the carriage 23 in front of the bracket 3Q by a screw or bolt 46. Beyond the front edge of the carriage 23, the spring 45 is bent upwardly and terminates in an overhanging lip 41 which carries a hardened insert 5|]. A friction brake 48 is I fastened to the spring .45 by a screw or bolt 53 directly over the track 21 and is urged into contact with the track 21 by the spring 45. The spring 45 is formed with a hole 5| surrounding the stud bolt 4|.

Two levers 52 are pivotally mounted on screws or bolts 53, one on each side of the spring 45. Spacers 54 on the screws or bolts 53 hold the levers 52 away from the front end of the carriage 23. The inner ends of the levers 52 bear against the insert on the under side of the overhanging lip 41 of the spring 45 and the outer ends of the levers 52 are provided with enlarged knobs 55. In order to limit the movement of the levers 52, two screws or bolts 55 project outwardly from the front of the carriage 23 through elongated slots 51 in the levers 52. These screws or bolts 56 are provided with spacers 58 similar to the spacers 54.

It can readily be seen that pressure on either chin rest I4. Upon release of the knobs 55, the spring 45 presses the brake 48 into engagement with the track 21 and locks the carriage 23 against transverse movement.

A circular recess 6| is formed in the center of the top of the carriage 23 and a tapped hole 62 63. and extends with the stud into the recess 6|.

An arm 86, which may be cast integral with'the bearing. sleeve 65 extends laterally therefrom and is bifurcated at the outer end to form two spaced ears 61. A transverse shaft 68 is journalled in bores 69 in the ears 61 and the micro-' scope arm I is fixed on the shaft 60 between the ears by a suitable screw or bolt .1] as shown in Figs. and 6. i

A transverse slot I2 is formed in the lower end of the microscope arm I0 to receive a stop I3 which is fixed to the arm 66 between the ears 6'! by a screw or bolt 74. The microscope arm I0 is thus free to swing on the shaft 68 and the swinging movement is limited by the width of the slot 12.

To insure return of the arm I0 to its proper vertical position, a cup-shaped member I5 is threaded into a tapped hole I6 in the lower end of the arm I0. A sleeve TI is fixed in a hole I8 in the arm 66 and contains a ball or detent I9 which is pressed toward the microscope arm I0 by a coil spring 80. A screw 8| in the bottom end of the sleeve 11 regulates the tension of the spring I9 and the top end of the sleeve 11 may be restricted or reduced to prevent the escape of the ball 19 as is well known in the art. When the arm I0 is in its proper vertical position, the ball I9 engages in the cup I5 and holds the arm I0 against displacement.

As shown in Fig. 5, the weight of the arm I0 tends to swing the arm counterclockwise away from its vertical position. To correct this, two counterbalancing springs 82 are secured atone end, one on the outside of each ear 61, by screws or bolts 83. The springs 82 are then wound around the shaft 68 and their free ends are positioned in transverse slots 84 in each end of the shaft 68. Covers 85 are secured on each end of the shaft 68 by screws 85 over the springs 82 and, if desired, the outside of the ears 61 may be recessed so that the covers 85 are flush with the sides of the arms 66 and 10 as shown in Fig. 1.

The arm I0 is curved adjacent the shaft 68 and the other end extends upwardlyparallel to the stud 63. A sleeve 86 is rigidly fastened in a bore 81 in the upper end of the arm I0. A tubular screw 88 is vertically slidably mounted within the sleeve 86 but is held against rotation by a key 89 which is secured to the sleeve 86 by a screw 90 and engages a vertical slot '9I in the tubular screw 88. A knurled nut 92 is threaded on the tubular screw 88 above the sleeve 86. to raise and lower the screw 88. This nut 92 is held against longitudinal movement relative to the sleeve 86 by a washer 93 which is seated in an annular groove 94 in the sleeve 86 and is fastened to the nut 92 by a collar 95.

A bearing 96 is threaded into the top of the screw 88 andthe screw 88 and bearing 96 are urged upward by a coil spring 91 which bears against the bottom of the bore 81 and the bottom of the bearing 96. A shaft 98 is rotatably mounted in the bearing 96 and may be locked in any angular position by a. set screw 99 which bears against the split sleeve I00 surrounding the shaft 98.

A conventional microscope slide IOI is fastened on top of the shaft 98. This slide IOI carries the usual microscope I02 provided with the usual interchangeable objectives IIO, which may be focused by the usual knobs I03. The construction of the microscope and focusing mechanism form no part of the present invention and are well known to those skilled in the art.

A second bearing sleeve I04 is rotatably mounted on the stud 63 above the sleeve 65. The slit lamp arm I05, which may be formed integral with the sleeve I04, projects outward and upward parallel to the microscope arm. This arm I05 is hollow like the arm I0 and carries an identical ele-, vating mechanism which is controlled by the nut 92. A shaft, not shown, but substantially identical with the shaft 98, is rotatable in a bearing 96 and may be locked against rotation by a set screw 99. A bracket I06 fixed on the end of shaft, not shown, and the slit lamp unit is mounted on this bracket I06.

This slit lamp unit includes a vertical lamp house I01 and a reflector I08 for directing the light from the lamp house in a horizontal direction. An objective lens is mounted in the movable sleeve I09 and may be moved back and forth by a rack and pinion mechanism, not shown, under the control of a knob III.

Current is supplied to the lamp by an electric cord or wire II2 which passes upward from the base through a central hole H3 in the stud 63. This wire enters the arm I05 at II4, coming out near the top of the arm I05 and entering the top of the lamp house I81. A suitable hand switch I I5 may be secured on the base II to turn the current on and off and the amount of illumination may be regulated by a suitable rheostat, not shown, under the control of a knob or handle H6.

The details of construction of the slit lamp unit form no part of the present invention and are well known to those skilled in the art.

It is sometimes desirable to swing the microscope I02 and slit lamp together as a unit. To accomplish this, an apron H8 is secured to the bearing sleeve I06 by screws or bolts H8. The lower portion of this apron II8 extends down beyond the bearing sleeve I04 and encircles the bearing sleeve 65 which is enlarged at the top as indicated at I in Fig. 5. A spring arm I2I is secured at the top of the apron II8 by a screw I22. The lower end of this arm I2I is formed with a brake shoe I23 which passes through a.

slot I24 in the apron II8 to bear against the sleeve 65. A screw I extends outwardly from the apron II8 through a hole I26 and carries an enlarged knurled nut I21. Ordinarily the spring arm I2I urges the brake shoe I23 away from the sleeve 65 but the shoe I23 may be moved into braking engagement by the nut I21.

A cover plate I28, threaded into the top of the stud 63, extends over the sleeve I04 and prevents the ingress of dust and dirt between the stud 63 and bearing sleeves 65 and I04. A hole I29 in the cover plate I28 permits the passage of the electric cord II2.

In using my new slit lamp microscope, the patients chin is placed on the chin rest I I and the chin rest is raised or lowered to a comfortable and convenient height by the nut I5. The forehead rest I6 is then moved forward or back by the screw I9 until the eyes of the patient are over the plane of the center of the stud 63, that is, over the pivotalaxis of the two arms I05 and 66. The carriage brake is then released by pressing one of the knobs 55 and the carriage 23 moved sidewise until the stud 63 is directly under one of the patients eyes.

The slit lamp projector is then lit by means of the switch H5 and its intensity regulated by the rheostat knob MI. The slit lamp projector is then raised or lowered on the arm I05 .by the nut 92' until it is level with the patients eye and the slit beam is focused on the eye by turning the knob H1 and moving the objective sleeve I09, The slit lamp projector can be directed into the eye at an angle by releasing the set screw 99 and turning the bracket I06 on the bearing 96.

fIhe microscope I02 is then raised to the level of the patients eye by the nut 92. The proper power objective H is selected and th microscope is focused on the eye by means of the knobs I03. The microscope I02 may be adjusted angularly by releasing the set screw 99 and tuming the microscope slide IUI on the bearing 96. The microscope counterbalancing spring 91 and the corresponding counterbalancing spring in the slit lamp arm I05, makes the raising and lowering of the microscope and slit lamp projector smooth and uniform.

Since both the microscope arm and the slit lam-p arm rotate on the stud 63 about an axis which passes through the eye of the patient, these arms may be moved without the need for refocusing either the slit lamp projector or microscope. The eye of the patient can thus be easily examined from varying angles and at varying angles of illumination.

It is sometimes desirable to move the microscope and slit lamp together through different angles while examining the eye and this may be accomplished by tightening the nut 21 and bringing the brake shoe I23 into contact with the sleeve 65.

When the positions of the slit lamp and microscope are to be reversed, as for example when the patients other eye is to be examined, the

microscope arm I0 is swung outward on the shaft 68 and the two arms III and I05 can pass without interference. Throughout the entire examination, the patients head remains fixed and both eyes can be examined while the head is in this one fixed position.

From the foregoing, it will be apparent that I am able to attain the objects of my invention and provide a new and improved slit lamp which is simple, efficient, convenient and compact. Various modifications can, of course, be made without departing from the spirit of my invention and the scope of the appended claims.

I claim:

1. In an eye examining apparatus having a base, a head rest on the base and pivotally mounted illuminating and observation devices rotatable either separately or together about a common axis, the combination therewith of a slidable carriage for supporting said illuminating and observation devices and spring pressed friction means for releasably locking the carniage at any point in its path of travel, said base having a track on its upper surface parallel to its front edge and a shaft supported thereon towards its rear edge in parallel relation to said track and the surface of the base, said carriage being slidably supported on said base by sleeved bearing means slidably engaging said shaft and by rotating bearing means contacting both sides of said track, said rotating bearing means being mounted upon said carriage near each side thereof and upon a bracket depending from the carriage and extending below said base.

2. In an eye examining apparatus having a base, a head rest .and pivotally mounted illuminating and observation devices rotatable either separately or together about a common axis, the combination therewith of a slidable carriage for supporting said illuminating and observation devices, said base being provided with .a slot parallel to its front edge and also with an enlarged opening adjacent thereto, a track supported in said s1ot,.a shaft supported on the upper surface of said base towards its rear edge in parallel relation to said track and to the surface of said base, sleeved bearing means on said carriage engaging said shaft and slidably supporting the rear of the carriage, a ball bearing assembly mounted on said carriage at each side of the front thereof, the outer ball race of each ball bearing assembly being in supporting and rolling contact with the upper surface of said track, a bracket secured to the underside of said carri-age and extending through the opening in said base and parallel to the under surface of the base, said bracket carrying a ball bearing assembly with its outer ball race in supporting and rolling contact with the under surface of said track, a leaf spring carrying a friction brake mounted on the under side of said carriage to normally maintain the brake in engagement with said track, and lever means mounted on the front edge of said carriage for engagement with said spring whereby said brake may be released.

3. In an eye examining apparatus having a base and a head rest mounted thereon, the combination of a carriage slidably mounted upon said base with spring pressed means for releasably locking the carriage at any point in its path of travel and a vertical stud supporting superposed bearing sleeves in freely rotatable relation to each other, one bearing sleeve having a support arm carrying an illuminatmg device and the other sleeve having a support arm carrying an observation device, an apron fixed to one sleeve and extending partly over the second sleeve, locking means comprising a spring with a brake thereon and a screw for moving said spring carried on said apron and normally out of contact therewith for locking said apron to the second sleeve whereby both sleeves may be simultaneously rotated, said base having a track on its upper surface parallel to its front edge, a shaft supported on the upper surface of said base in parallel relation to said track and to the surface of the base, said carriage being slidably supported on said base by sleeved bearing means slidably engaging said shaft and by rotating bearing means contacting both sides of said track, said rotatmg bearing means being mounted upon said carriage near each side thereof and upon a bracket depending from the carriage and extending below said base.

FREDERICK W. JOEE. 

